In which weather system do winds blow anticlockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere?

A cyclone is a system of winds blowing around a centre of low pressure. In the Northern Hemisphere, the winds in a cyclone blow inwards in an anticlockwise direction, and in the Southern Hemisphere they blow in a clockwise direction.

The direction of rotation is caused by the Coriolis force, which results from the rotation of the Earth. This force deflects moving air (and water) to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. The Coriolis force is zero at the equator, which is why tropical cyclones do not form within about 5° of the equator. In an anticyclone, which is a system of winds blowing outwards from a centre of high pressure, the direction is the opposite: clockwise in the Northern Hemisphere and anticlockwise in the Southern Hemisphere. Anticyclones usually bring calm, clear and dry weather.

Tropical cyclones form over warm tropical oceans, where the sea surface temperature is above about 27°C. They bring very strong winds, heavy rain and storm surges, and cause great damage when they reach the coast. The calm centre of a cyclone is called the "eye", surrounded by the "eyewall", where the winds are strongest. Tropical cyclones have different names in different regions:

In India, the Bay of Bengal experiences more cyclones than the Arabian Sea, and the coasts of Odisha, Andhra Pradesh and West Bengal are most affected. Cyclones in the north Indian Ocean are named from a list prepared by the countries of the region, under the World Meteorological Organization.

Why not the other options?

• ✗Anticyclones have winds blowing clockwise in the Northern Hemisphere, the opposite direction.
• ✗Trade winds blow from the sub-tropical highs towards the equator.
• ✗Westerlies blow from the sub-tropical highs towards the sub-polar lows in middle latitudes.